A wireless communication device uses an antenna to emit radio frequency signals into the air. In some cases, the wireless communication device uses different frequency bands for different wireless communications, but the device only has single antenna. Unfortunately, the size of the single antenna cannot be optimized for both frequency bands. Thus, wireless communication performance at one or both of the frequency bands is impaired.
The wireless communication device may use a multi-band antenna system with multiple antenna elements that are coupled through an array of switches. Unfortunately, a physically separate switch control network is required to operate the switches and configure the antenna system. This relatively complex antenna control system may not be desirable for smaller devices, such as laptop computers and smart phones.
Overview
In a wireless communication device, circuitry selects a first frequency band for a first wireless communication and transfers a pair of radio frequency signals at the first frequency band. An antenna receives and orthogonally transmits the radio frequency signals over a first patch antenna element that is resonant at the first frequency band. The circuitry selects a second frequency band for a second wireless communication and transfers a pair of radio frequency signals at the second frequency band and including a voltage component. The antenna receives the radio frequency signals including the voltage component and couples a second patch antenna element to the first patch antenna element in response to the voltage component. The antenna orthogonally transmits the radio frequency signals over the coupled patch antenna elements that together are resonant at the second frequency band.